Science: Prizes

Four years ago, when Marie Curie was still alive, her old heart was proud that her shy young daughter and her brilliant young son-in-law were showing themselves to be able and devoted scientists. In the Curie Laboratory of Paris’ Institut du Radium Irène Curie-Joliot and Jean Frederic Joliot were shooting alpha particles (nuclei of helium atoms) at the lightweight element beryllium. Strange rays hopped out of the beryllium. Fed into paraffin, the rays knocked out protons (hydrogen nuclei) at dizzy speeds ofone-tenth the velocity of light. What were the strange rays?

In England was an astute physicist, just past 40, whose experiments in science had continued even while he was interned in Germany during the War. Dr. James Chadwick, working under Lord Rutherford in Cambridge University’s Cavendish Laboratory, was studying the same strange rays obtained by the Curie-Joliots. He found that they were electrically neutral like light but were actually particles 1,845 times as heavy as electrons. Thus was discovered the neutron (TIME, March 7, 1932). The Curie-Joliots confirmed his discovery, showed that neutrons behaved as only electrically inert particles could.

In Paris last year the Curie-Joliots were firing alpha particles at another light element—boron. Neutrons leaped out. But after the bombardment stopped, the boron continued to emit positive electrons as though the attack had stirred it into a sort of radioactivity. This unlooked-for discovery made necessary a new phrase: artificial radioactivity (TIME, Feb. 12, 1934)

From the shoulders of these two finds, atomic destruction and transmutation took fresh impetus the world over. Unencumbered by electric charges, neutrons as atom-wreckers are like wrestlers slippery with oil. They slide through the electronic field guarding the nucleus, do not swerve until they strike the hard core. Dr. Ernest Orlando Lawrence, who has an 85-ton magnet to play with on the University of California campus, produced a beam of 10,000,000 neutrons a second by smashing lightweight elements with deutons (nuclei of heavy hydrogen). With “slow neutrons” lately it has been found possible to produce gamma radiation from silver. For mathematical reasons that physicists find increasingly hard to translate into English, slow neutrons braked by a paraffin shield have more effect on the target than fast ones, are currently lionized in every physics journal.

The Curie-Joliots’ first results in artificial radioactivity have been duplicated and extended in a half-dozen countries, especially by California’s Lawrence and Italy’s Fermi. Dr. Lawrence obtained 5,000,000-volt gamma rays from salt, evoked the possibility of injecting harmless but radioactivated salt compounds into the human body as a cancer remedy. Dr. Fermi has coaxed radiations of betaparticles (fast electrons) from phosphorus, iron, silicon, aluminum, chlorine, vanadium. copper, arsenic, silver, tellurium, iodine, a dozen others.

To Dr. James Chadwick, discoverer of neutrons, the Swedish Academy of Science last week awarded the Nobel Prize for Physics. Irene and Jean Frederic Curie-Joliot, discoverers of artificial radioactivity, were awarded the Nobel Prize for Chemistry. The money (about $41,000) will come in handy, but even more cherished by the Curie-Joliots will be the scroll which they can now put beside the one Pierre & Marie Curie won in 1903, and the one Marie Curie won alone in 1911.